Mobile ad network Millennial Media revealed during its Q1 earnings call Wednesday that although quarterly revenue is up, the company continues to bleed money and CFO Michael Avon is stepping down. As a result of its dismal report, the company's shares tumbled 45% in after hours trading, hovering in the $3 range.

While Millennial Media reported $72.6 million in revenue for the first quarter, up from $49.4 million in Q1 2013 (a 46.9% year-over-year increase), it also reported a Q1 loss of $12.9 million, compared to a $3.8 million loss for the same quarter last year. Millennial provided a lowered outlook for Q2, with revenue forecasts ranging between $70 million and $75 million.

Wall Street was greatly disappointed with the low guidance (analysts were forecasting $96.4 million next quarter).

CEO Michael Barrett also acknowledged that Millennial's app download business had greatly weakened between Q4 and Q1. Part of the drop off was seasonal but “other players” were also taking “significant market share,” he said.

“Millennial has relied on a few large performance advertisers to generate revenue … without focusing on accommodating a broader market,” Barrett said. “This has to change.”

Millennial’s strategy includes expanding its programmatic presence to shift lower dollar campaigns into automated solutions while freeing up sales, data and management teams to focus on working with large, high-touch clients.

Revenue from the company’s ad exchange, MMX, is not yet significant, but is expected to show significant results in the coming quarters, according to Avon.

Avon, who had been an early investor in Millennial before becoming its CFO about eight years ago, also said that he was leaving the company to pursue “his entrepreneurial roots.”

During the fourth quarter, Millennial said it had about 625 million monthly unique user profiles globally and 170 million monthly unique users in the US. The profiles consist of behavioral, usage and location data points and patterns that Millennial offers to advertisers through direct sales.

The company said it is up to 650 million monthly unique user profiles globally while remaining steady at 170 million users in the US. Millennial also said approximately 60,000 apps and mobile sites were operating on its platform (up from 50,000 in Q4).

Whereas Barrett initially demurred from discussing Millennial's plans for monetizing its user profile database in the fourth quarter, he warmed up considerably to the idea of offering the company's user profiles programmatically to mobile buyers.

Barrett noted during today's call that the company has been able to monetize its user data by offering it through direct sales and it could help advertisers drive even more impressions by opening up its data to external sources.

Millennial Media was an ad tech darling when it issued an IPO two years ago at approximately $13. Much has changed since then. The company now faces intense competition from Google, Facebook and Twitter. The latter two launched ad networks in April and, like Google, command huge amounts of user data.